The LONDON TRANSPORT Volvo Cumulo Citybus: C1

This page created 16th June 2001 by Ian Smith, updated 2nd February 2003.

The Volvo Cumulo Bus: C1

C1 was one of London Transport's one-off experimental buses.
It looks rather like a Volvo Ailsa, but was more interesting than that.
It was a "London special", a one-off, a Volvo Citybus with underfloor engine
with a hydraulic pump/motor and energy accumulator (Volvo Flygmotor Cumulo)
connected between the gearbox and differential.
While the bus was stopping the accumulator
collected kinetic energy, and released it during acceleration, reducing the engine load.

It had an Alexander R body with dual doorway
like contemporary Scottish Volvo Ailsas and London Ailsas V1 and V2.
In London days it had centre exit doors too. London Transport leased it for three years
from August 1985 as part of their Alternative Vehicle Evaluation, numbering it C1.
It didn't enter service until July 1986, when it worked on route 102 from Palmers Green (AD).
After the trials, in September 1987, it was returned to Volvo.
The Cumulo system was replaced by a standard ZF gearbox before its sale to McMenemy of Ardrossan,
a member of the A1 Service consortium. It quickly passed on to Black Prince of Morley.
(who have had an interesting collection of ex-LT buses).

Unlike the Ailsas it has remained in service into the new century,
and I saw it in Leeds in January 2001, dressed in one of Black Prince's individual but thematic liveries.

Photos by Ian Smith: click them for larger versions.

"That's a London registration" I thought, as I pushed a wheelchair down to the City Centre bus-stop in Leeds.
I don't remember what happened to the wheelchair,
but my camera came out of my pocket in under a second.
These are the resulting pictures. Well, what sort of quality do you expect at three o'clock on
a dull January Day in the rain in Leeds?